AWWA ACE61620

A simulation model was derived to describe the filtration and accumulation of three classes of antibiotics in slow sand filters. Verification was evaluated by extracting a macrolide antibiotic from the schmutzdecke of a pilot slow sand filter subjected to a 60 day challenge experiment. The study also examined schmutzdecke sorption behavior and removal efficiencies in the pilot filter fed 0.2 mg/L of five antibiotics. Aqueous antibiotic concentrations were analyzed by HPLC MS/MS. Schmutzdecke sorption coefficients were comparable to those previously found for soils and did not correlate well with estimates derived from octanol/water partition coefficients. At the end of a 14-day slow sand filtration period, tylosin was not detected in filter effluent and trimethoprim was > 99% removed. However, slow sand filtration exhibited < 25% removal of lincomycin and < 4% removal of the sulfonamide class of antibiotics. Slow sand filtration is regarded as an ineffective treatment method for antibiotics with low filter media sorption coefficients. Includes 7 references, figures.